These are some common data types you'll see throughout the course (probably).

Integer (int): can be signed (int) or unsigned (uint); whole numbers only (32-bit signed/unsigned).

• Unsigned integers range from 0 to 4,294,967,295
  • Example: uint barbaz = 4294967295;
• Signed integers range from -2,147,483,648 to 2,147,483,647
  • Example: int foobar = 2147483647;

Float (float): holds floating-point values; decimals or whole numbers (32-bit signed).

• Example: float foobaz = 1.234;

Double (double): holds floating-point values; decimals or whole numbers (64-bit signed).

• Example: double barbaz = 1.234;

Decimal (decimal): holds floating-point values; decimals or whole numbers (128-bit signed).

• Example: decimal foobar = 1.234;
  • Float, double, and decimal *practically* do the same thing.
  • If you're concerned with accuracy and don't care about performance, use decimal.
    • If you want speed and don't mind *minor* inaccuracies in calculations, use either float or double.

String (string): holds unicode data.

• Example: string foobar = "This is a string";

What the hell does all this mean??

Chill! Odds are you'll never need (or want) to know/understand everything I said on this page.
The important things to take away from this are as follows:

• If you're playing with whole numbers (that is, things that don't have decimals), then the int datatype is your friend.
• If you're handling things that contain decimals, then you'll want to use one of the float, double, or decimal datatypes.
  • See my notes above to help you figure which is best in your situation.
• If you're handling things with letters, you'll obviously be dealing with strings and thus need to use the string datatype.

Extra important:

This should go without saying, but I'm saying it anyway -- you CANNOT perform mathematical operations on non-similar datatypes. That is to say, that you cannot take the string "Kittens" and try to multiply it by the int "2"; trust me, bad things will happen.

This is especially important when dealing with *user input* as while input may look like an integer/decimal/float/double, it can (and probably will be) a string!

Example (this will not work as it is attempting to perform math on unlike types):

string foobar = "2";
int barbaz = 2;
int foobaz = foobar + barbaz;

To overcome this, you must first cast/convert the string foobar to an integer.

string foobar = "2";
int barbaz = 2;
int foobaz = Convert.ToInt32(foobar) + barbaz;

See this list from Microsoft for more information on the Convert method: http://msdn.microsoft.com/en-us/library/system.convert_methods.aspx